Chamfering tool



Patented Oct. 16, 1951 GHAMFERING'TOOL' Wilber W, Yawter, Indianapolislndi.

Application April "I, 1948, Serial'No. 19,462..

(01'. vac-73.5

The present invention relates primarily to a chamferingtool, though it is applicable to any type of rotary toolincluding a bit having-"an acti've-portion shiftable between a position in which such portion is entirely shrouded; and apos-ition in'which such portion projects into a locationof action. Since the-invention is highly adaptable for-"use in cha-m-fering tools, it has been soill ustrated, and will be so described;

The primary object of the invention isto provide-improved means fer-shifting the bit between According to my-invention, actuating'means forthe bit is provided of such character that the application of'a' slight braking force to the actuating means; which presents a smooth surface concentricto the axisof rotation cf'the tool; will result in the desired shifting of the hit. Ancillary objectives ofthe invention are to provide refinements in the construction offthe actuating means for the bitof such 2; took.

To the accomplishment of, the above and related objects, my invention maybe embodied in the form illustrated in the accompanying drawings, attentionbeing called to the fact, however, that the drawings are illustrative only; and that change may bemade in the specific; construction illustrated and described, so, long as the scope of the appended claims: is not violated;

Fig. 1- is a perspective view of a chamfering tool constructed in accordancewith myinvention, parts being brokenaway or'showrr in: section: for clarity of illustration;

Fig". 2 is an axial section through such a tool;

Fig. 3 is a transverse section taken substantiallyon the line 3'-3 of Fig. 2;

Fig. 4 is a transverse section taken substantially on the line; 4& of Fig. 2' and. looking in the direction of. the arrows;

Fig. 5 is a transverse sectiontaken; substantially on the line 55 of Fig. 2 and looking in the direction of the arrows, and

Fig;v 6' is a transverse section taken substantially on the line &6. at Fig. 21

Referring. more particularly toe the drawings, it; will? bexseenthat. my tool; comprises a shaft: indicated generally by the reference numeral to. In: the illustrated. embodiment: of" the invention, and for facility of manufacture; the shaft Id is made in two parts, comprising a major section I I having an axially-extending, radially-opening slot [-2 therein opening through the end l3 of the section H; and a minorsection I 4, formed with a longitudinally extending, substantially. radially-opening slot 15, opening through the end l-6 of said section. The end l3 of themajor-section I' l is bored to receive the end l6: of the section [4, with the slots I2 and; [5 in registry. It will be perceived that the shaft lllv might comprise an integral piece, but that the formation of the slot I2-I5 is facilitated by the illustrated arrangement, and that the two-part arrangement further makes it possible to harden the minor section M, which issubjectedto primary wear, and to replace only that section when it does become worn.

A bit l 1 is received in the slot l' 2-l'5.. Adjacent one end; said bit is formed with an. active portion or blade l8 which is adapted to be-shifted between-the-proj ecting, solid line-position and the retracted, dotted line position. Adjacent its op posite end, the'bitis: formed with a radially" projecting portion: 19, alwayslocated outside the slotl2; and bifurcated'to form a notch 20, in the manner clearly: illustrated in Figs. 1 and 2.

A screw 2| is' received in a chordal bore. 22 formed in the shaft section H, and a transverse notch 23 in: the shaft section I4 registers with said bore, so that the screw- 2I' engages in said notch to hold theshaftsection l4. rigidly with respectto the section H The screw 2| also. passes freely through an aperture 24 in the bit [1, whereby said screw constitutes a pivotal mount.- ing' for said: bit, permitting-- rocking" movement of said; bit between the solid, line and dotted line positions oi 'Fig; 2:.

A collar 25 is sleeved on the shaft section H to overlie the upper end of the bit IT, and is formed, in. its upper end: surface, with an annular recess -2fihauing-an: enlargement ZT'for the accommodation of the bit portion [9; A set screw 28, or otherequivalentrmeans, is provided for fixing the collar 251 rig-idly in position upon the shaft section ll'lf.

Loosely sleeved on the shaft section H; is a second collar 2'9 provided with a smooth cylindrical exterior.- surface concentric with said shaft section. At one end, the collar-29 firmly" but loosely: abuts: the upper end surface of the collar 2 5 to. closethe recess: 25; and said end of the collar 2K formed with an axiallyextending, peripherally elongated, eccentricrib 30" which projects into the recess 26: of the collar 25; As is clearly to be seen in Figs. 2: and 4, the rib 30 is: received: in the notch 20 ofthe bifurcatedportion [9'- of" the bit I 1, so that the iurcations of saidbit portion bearagainstthe inner and outer peripheral surf-aces of therib 30. Since the rib 301 is. eccentric, asis clearly shown in Fig. 4, rotary or oscillatory movement of the collar 29 relativerto the shaft section M will obviously resuit in radial movement-of the portion I 9 of the bit 1, to rocksaid bit about the axis of the screw- 29 to shift the active portion l8 ofsaid bitbetween the positions illustrated in solid lines and 'in dhtted lines iii-Fig.2".

The rib 30 is interrupted, as at 31 and a pin 32, which projects substantially radiallyfrom the shaft II, is located within the interruption 3|, where it is engageable by the ends of the rib definin the interruption 3|, to limit relative oscillatory movement between the collar 29 and the shaft section I l.

The upper end surface of the collar 29 is formed with an annular socket 33 in which is received a coiled torsion spring 34, which is sleeved on the shaft section II with one end 35 thereof anchored upon said shaft section and the other end 38 thereof anchored upon the collar 29. Thus,the spring 34 will resist clockwise movement of the collar 29, as viewed in Fig; 3, relative to the shaft section I I and, whenever no exmovement of said collar relative to said shaft, resilient means resisting such rotary movement in one direction, and cam means operatively connecting said collar and said bit to rock said bit about said fulcrum means in response to rotary movement of said collar relative to said shaft.

ternal force is applied to said elements, will hold the collar 29 in the position illustrated in Fig. 4, wherein the bit I! assumes the position illustrated in solid lines in Fig. 2.

A third collar 31 is located on the shaft section II in abutment with the upper end face of collar wherein it will be rotated in a counter-clockwise direction as viewed from the lefthand end of Fig. 1. So long as no braking force is applied to the collar 29, the parts will maintain their illustrated relative positions, wherein the blade l8 projects slot upon such rocking movement of saidbit, a

radially beyond the confines of the shaft section ll. If, however, the periphery of the collar 29 is grasped by an operator, or braked in any other manner, the retarding effect will cause the shaft H to run ahead of the collar 29, whereby the pin 32 will be moved through the interruption 3| in the rib 30, to engage the rib end which is remote from said pin, as shown in Fig. 1. Thereby, the rib 30'will be caused to move relative to the bit I! to shift a portion of said rib more remote from the shaft axis into registry with the straddling furcations of the bit portion l9, and the bit will be shifted to the position illustrated in dotted is withdrawn A 2. The tool of claim 1 in which said resilient means normally holds said collar in a position in which said active portion of said bit is projected.

3. The tool of claim 1 in which said cam means comprises an axially-extending trackway at one end of said collar, eccentric relative to said shaft axis and elongated peripherally thereof, and-in which the other end of said bit has a two-way positive engagement with said trackway.

4. The tool of claim 1 in which said cam means comprises an axially-elongated rib at one end of said collar, eccentric relative to said shaft axis and elongated peripherally thereof, and in which the other end of said bit bears against a peripheral surface of said rib. I

5. The tool of claim 4 in which said other end of said bit is bifurcated and bears against the inner and outer peripheral surfaces of said rib.

6. A tool comprising a shaft provided with an axially-elongated substantially radially-opening slot, a bit received in said slot, pivot means traversing said slot and engaging said bit intermediate the ends thereof to support said-bit for rocking movement about said pivot means, said bit having an active portion adjacent one end projectible from, and retractable into, said collar fixed to said shaft, overlying the other end of said bit and formed to provide anannular recess in its face remote from said first-named bit end, said other end of said bit being provided with a portion projecting into said recess, a second collar loosely sleeved on said shaft and abutting the recessed end of said first-named collar, said second collar having, on its face abutting said first-named collar, a peripherally-extending, axially-projecting, interrupted rib-projecting into said recess,v said projecting bit portion being bifurcated to straddle said rib, means projecting substantially radially fromsaid shaft into said recess and located within the interrupted portion of said rib to limit relative movement between tion upon the collar 29 positively results in shifting of the bit blade [8 to its inactive position;

and said blade will be returned to active position instantaneously and automatically upon release of the collar 29.

I claim as my invention:

1. A tool comprising a shaft adapted to be robit rocks about said fulcrum means, between a position within said slot and a position projecting therefrom, a collar sleeved on said shaft, means restraining said collar against axial movement relative to said shaft, means limiting rotary said second collar and said shaft about the axis of said shaft, the other end face of said second collar being provided with an annular socket, a coiled spring sleeved on said shaft within said socket with one end anchored on said shaft and its other end-anchored on said second collar, and a third collar fixed on said shaft and abutting said last-named face ofsaid second collar to close saidsocket. 1

-WILBER W. VAWTER.

REFERENCES CITED V The following references are of record in. the

' file of this patent:

UNITED STATES PATENTS Number Name Date 348,412 Perrigo Aug. 31, 1886 1,547,108 .Ellis July 21, 1925 2,207,067 Patscheider July 9, 1940 2,258,097 -Menaquale Oct. 7, 1941 2,314,084 Fried Mar. '16, 1943 2,433,976 Babka -Q Jan. 6, 1948 FOREIGN PATENTS Number Country Date 7 28,967 Great Britain Sept 15, 1910 

